Tweak and reword release notes

doc/notes/notes-9.18.31.rst

@@ -24,34 +24,21 @@ New Features
 Feature Changes
 ~~~~~~~~~~~~~~~
 
-- Allow IXFR-to-AXFR fallback on DNS_R_TOOMANYRECORDS.
+- Allow IXFR-to-AXFR fallback on ``DNS_R_TOOMANYRECORDS``.
 
   This change allows fallback from an IXFR failure to AXFR when the
-  reason is `DNS_R_TOOMANYRECORDS`. This is because this error condition
-  could be temporary only in an intermediate version of IXFR
-  transactions and it's possible that the latest version of the zone
-  doesn't have that condition. In such a case, the secondary would never
-  be able to update the zone (even if it could) without this fallback.
-
-  This fallback behavior is particularly useful with the recently
-  introduced `max-records-per-type` and `max-types-per-name` options:
-  the primary may not have these limitations and may temporarily
-  introduce "too many" records, breaking IXFR. If the primary side
-  subsequently deletes these records, this fallback will help recover
-  the zone transfer failure automatically; without it, the secondary
-  side would first need to increase the limit, which requires more
-  operational overhead and has its own adverse effect. :gl:`#4928`
+  reason is ``DNS_R_TOOMANYRECORDS``. :gl:`#4928`
 
 Bug Fixes
 ~~~~~~~~~
 
-- Fix a statistics channel counter bug when 'forward only' zones are
+- Fix a statistics channel counter bug when "forward only" zones are
   used.
 
-  When resolving a zone with a 'forward only' policy, and finding out
-  that all the forwarders are marked as "bad", the 'ServerQuota' counter
-  of the statistics channel was incorrectly increased. This has been
-  fixed. :gl:`#1793`
+  When resolving a zone with a "forward only" policy, and finding out
+  that all the forwarders were marked as "bad", the "ServerQuota"
+  counter of the statistics channel was incorrectly increased. This has
+  been fixed. :gl:`#1793`
 
 - Fix a bug in the static-stub implementation.
 
@@ -61,29 +48,26 @@ Bug Fixes
   addresses being used instead of the correct server addresses.
   :gl:`#4850`
 
-- Don't allow statistics-channel if libxml2 and libjson-c are
-  unsupported.
+- Don't allow :any:`statistics-channels` if libxml2 and libjson-c are
+  not configured.
 
-  When the libxml2 and libjson-c libraries are not supported, the
-  statistics channel can't return anything useful, so it is now
-  disabled. Use of `statistics-channel` in `named.conf` is a fatal
-  error. :gl:`#4895`
+  When BIND 9 is not configured with the libxml2 and libjson-c
+  libraries, the use of the :any:`statistics-channels` option is a fatal
+  error.  :gl:`#4895`
 
 - Limit the outgoing UDP send queue size.
 
-  If the operating system UDP queue gets full and the outgoing UDP
-  sending starts to be delayed, BIND 9 could exhibit memory spikes as it
-  tries to enqueue all the outgoing UDP messages.  Try a bit harder to
-  deliver the outgoing UDP messages synchronously and if that fails,
-  drop the outgoing DNS message that would get queued up and then
+  If the operating system UDP queue got full and the outgoing UDP
+  sending started to be delayed, BIND 9 could exhibit memory spikes as
+  it tried to enqueue all the outgoing UDP messages. It now tries to
+  deliver the outgoing UDP messages synchronously; if that fails, it
+  drops the outgoing DNS message that would get queued up and then
   timeout on the client side. :gl:`#4930`
 
-- Do not set SO_INCOMING_CPU.
+- Do not set ``SO_INCOMING_CPU``.
 
-  We currently set SO_INCOMING_CPU incorrectly, and testing by Ondrej
-  shows that fixing the issue by setting affinities is worse than
-  letting the kernel schedule threads without constraints. So we should
-  not set SO_INCOMING_CPU anymore. :gl:`#4936`
+  Remove the ``SO_INCOMING_CPU`` setting as kernel scheduling performs
+  better without constraints. :gl:`#4936`
 
 
 Known Issues